[cx-oracle-users] Stuck at "Python version 3.5 required, which was not found in the registry."

[Tipps, G. (G. Tipps) <rt...@ut...>]

Hello cx_Oracle users,

I have a 64-bit Windows Server 2012 R2 box that is running 32-bit Python 2.7.4 and uses cx_Oracle to connect to an Oracle 11g database, and I am trying to upgrade to 32-bit Python 3.5.

For Python 2.7.4 I was able to use the PyPi .exe installer (page link: https://pypi.python.org/pypi/cx_Oracle/), but the Python 3.5 installer (cx_Oracle-5.2.1-11g.win32-py3.5.exe) always gives me this error: "Python version 3.5 required, which was not found in the registry."

Some Googling of that led me to a blog post (link: http://codeyarns.com/2012/04/28/python-version-not-found-in-registry-error/) where the author was able to get around this error by creating some new registry keys- It turned out that in their case, the module was looking for some values under HKEY_CURRENT_USER\SOFTWARE\Python\PythonCore\3.2 , and  those values were actually written by the Python installer at HKEY_LOCAL_MACHINE\SOFTWARE\Python\PythonCore\3.2. They were able to export the HKLM values, edit the .reg file, then import them into HKCU, and successfully install the module.

I noticed that in my case, since I am working with 32-bit Python on a 64-bit system, those keys were written at HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Python\PythonCore\3.2, so I tried exporting the Wow6432Node\Python key and importing it in these three locations:
HKEY_CURRENT_USER\SOFTWARE\Python
HKEY_CURRENT_USER\SOFTWARE\Python\Wow6432Node
HKEY_LOCAL_MACHINE\SOFTWARE\Python

I rebooted the server after making these changes and ran the installer again, and was still met with the "Python version 3.5 required" error. I tried to find the registry path the installer is checking by inspecting the source code (https://bitbucket.org/anthony_tuininga/cx_oracle), but I wasn't able to find that error string. Can anyone here point me in one direction or another?

P.S. I'm trying to keep this message short, but: I have also tried to build & install the cx_Oracle module using pip, and while the server has 10 separate versions of the MS Visual C++ redistributable and the 11GB MS Video Studio Community 2015 package installed, that build attempt always fails at "error: Unable to find vcvarsall.bat" so I'm hoping the registry issue with the binary installer might be easier to resolve.

--Greg